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Home , Amine, Tertiary (chemistry)

Chapter 6 and

Nitrogen-Containing Functional Groups • is in Group V of the periodic table, and in Chapter 6 most of its compounds, it has three single bonds and one : Amines and Amides N

Chapter Objectives: • In this chapter, we will take a look at two functional • Learn to recognize the and functional groups. • Learn the IUPAC system for naming amines and amides. groups which contain nitrogen connected to • Learn the important physical properties of the amines and amides. carbons: the amines and the amides. • Learn the major chemical reactions of amines and amides, and learn how to predict the O products of amide synthesis and reactions. • Learn some of the important properties of condensation polymers, especially the . RR''N RCN R'

Mr. Kevin A. Boudreaux Angelo State University R' R" CHEM 2353 Fundamentals of Amine Amide Organic and for Today (Seager & Slabaugh) www.angelo.edu/faculty/kboudrea 2

Amines • Amines and amides are abundant in nature. They are a major component of and enzymes, nucleic , drugs, etc. ( are N- containing, weakly basic organic compounds; thousands of these substances are known.)

• Amines are organic derivatives of , NH3, in which one or more of the three H’s is replaced by a Classification and carbon group. • Amines are classified as primary (1°), Nomenclature of Amines (2°), or tertiary (3°), depending on how many carbon groups are connected to the nitrogen .

HHN RHN RHN RR''N

H H R' R' Ammonia 1° Amine 2° Amine 3° Amine 3 4

Examples: Classifying Amines Nomenclature of Amines • Classify the following amines as primary (1°), • Simple 1°, 2°, and 3° amines: common (trivial) secondary (2°), or tertiary (3°). names are obtained by alphabetically arranging the names of the on the nitrogen and H CH3 NH2 adding the suffix -amine (e.g., ethylmethylamine). • Amines in the IUPAC system: the “e” ending of CH3CH2CH2 N H CH3 N CH3 CH3CH2CHCH3 the name for the longest chain is replaced with –amine. The amine group is located by the position number. Groups that are attached to the nitrogen atom are located using “N” as the position H number. More complex primary amines are named with —NH2 as the amino . N CH3CH2 N CH3 N • Aromatic amines: named as derivatives of the NH2 H parent compound . Substituents attached to the nitrogen are indicated by using “N-” as the location number.

5 aniline 6 Chapter 6 Amines and Amides

Examples: Nomenclature of Amines Examples: Nomenclature of Amines • Provide common names for the following 2° and 3° • Provide common names for the following 2° and 3° amines; for 1° amines, provide common and/or amines; for 1° amines, provide common and/or IUPAC names where possible. IUPAC names where possible.

H NH2 CH3

CH3 NH2 CH3 NCH3 CH3CH2CH2CHCH3 CH3 NCH3

H NH CH 3 CH3CHCH2CH2 NH2 CH3 NCH2CH3 CH3CH2CH2 NH2 CH CH CH CHCH 3 2 2 3 NH2

7 8

Examples: Nomenclature of Amines Examples: Nomenclature of Amines • Provide common names for the following 2° and 3° • Provide names for the following aromatic amines. amines; for 1° amines, provide common and/or IUPAC names where possible. NH CH3 NH2

OH

ONH2 NH2 CH3

CH3CCH2CH2CH2CHCH3 CH3 CH3 CH3 CH2CH3 N N

9 10

Examples: Nomenclature of Amines Examples: Nomenclature of Amines • Provide names for the following aromatic amines. • Draw structural formulas for the following molecules: – ethylisopropylamine CH3 CH3 CH3 H N N

– tert-butylamine

CH3 CH2CH3

CH3 CH3 N – 2-pentanamine

CH3CH2 CH3 11 12 Chapter 6 Amines and Amides

Examples: Nomenclature of Amines Examples: Nomenclature of Amines • Draw structural formulas for the following molecules: • Draw structural formulas for the following molecules: – N-methyl-2-propanamine – N-methyl-2-chloroaniline

– 1,6-diaminohexane – N,3-diethylaniline

– 3-amino-1-propanol – N,N-

13 14

Physical Properties of Amines: H-Bonding • 1° and 2° amines can bond to each other:

CH3 N H CH3 N CH3

H H H H Physical Properties of CH3 N H N H CH3 N H N CH3 H CH3 CH3 CH3 Amines • 3° amines cannot to each other:

CH3 NCH3

CH3 CH3 X CH3 N CH3X N CH3

15 16 CH3 CH3

Physical Properties of Amines: Boiling Points Physical Properties of Amines: Boiling Points • Nitrogen is less electronegative than oxygen, so the Boiling Point: N—H bond is not quite as polar as the O—H bond. Carboxylic – Hydrogen bonds from N—H’s are not as strong as those resulting from O—H’s. 1°/2° Amines – Hydrogen bonding between 1° and 2° amines is 3° Amines/ not as strong as those found in alcohols or carboxylic acids. Molecular Boiling Name weight point • 1° and 2° amines have lower boiling points than alcohols of similar molecular weight. Acetic acid 60.0 g/mol 118°C 1-propanol 60.1 g/mol 97°C • 3° amines, since they do not hydrogen bond to each other, have boiling points similar to hydrocarbons of propyl amine 59.1 g/mol 48°C the same molecular weight. ethylmethylamine 59.1 g/mol 36°C 59.1 g/mol 2.9°C butane 58.1 g/mol -0.5°C 17 18 Chapter 6 Amines and Amides

Physical Properties of Amines: Water Physical Properties of Amines: Odor • 1°, 2°, and 3° amines can all form hydrogen bonds • Low molecular-weight amines tend to have sharp, with water. penetrating odors similar to ammonia • Low-molecular weight amines are generally water- • Higher molecular-weight amines often smell like soluble. rotting fish, and are often found in decaying animal tissues. NH NH H H H 2 2 O O O CH3 N CH3 CH2CH2CH2CH2 CH2CH2CH2CH2CH2 H H H H H CH3 NH2 NH2 CH3 N H O CH3 N H O CH3 N CH3 Trimethylamine 1,4-Diaminobutane 1,5-Diaminopentane H H CH H CH Responsible for the (Putrescine) (Cadaverine) 3 3 odor of rotting fish A poisonous oil present in A poisonous, viscous liquid O rotting flesh; produced present in rotting flesh; HH during the decomposition of produced during the the ; also decomposition of the amino partially responsible for the acid ; also partially odor of urine and bad breath responsible for the odor of 19 urine and bad breath 20

Examples: Predicting Physical Properties Examples: Predicting Physical Properties • Arrange the following compounds in order of • Which member of each of the following pairs of increasing boiling point. (All of the compounds compounds would you expect to have a higher have about the same molecular weight.) boiling point? propanoic acid, diethylamine, 1-butanol, – 2-aminopropane or 2-aminohexane ethyldimethylamine

– triethylamine or 1-aminohexane

– propanoic acid or diethylamine

– 1-pentanol or 1-aminopentane

21 22

Important Alkaloids

O O CH3 CH3 H CH 3 N H N N N N CH N 3 O N O N N N Nicotene CH 3 CH3 Found in tobacco plants; mild Caffeine Theobromine in small doses; Found in the seeds of Coffea arabica, Found in the seeds of addictive, but not especially Some Important roasted coffee beans; inhibits the action of Theobroma cacao; the harmful itself phosphodiesterase, an enzyme which stimulating ingredient in inhibits cyclic adenosine monophosphate chocolate. (AMP), which is responsible for forming Alkaloids in the bloodstream CH3 N HO N

CH3O

N Dextromethorphan Quinine 23 CH3O 24 Ingredient in cough suppressants. Antimalarial drug from cinchona tree Chapter 6 Amines and Amides

CH3 CH3 CH3 O O CH2CH3 N O N N H N N CH CH OCH 2 3 3 O CH3O H H N CH H H H N 3 O O O H H O O O OH Melatonin A naturally occuring hormone produced in the pineal gland; its production is triggered by the N absence of light; causes drowsiness in humans H Lysergic acid diethylamide (LSD) at night, triggers birds to migrate, and signals A synthetic hallucinogen from alkaloids obtained OH dogs to shed their winter coats; sold as a from ergot, a fungus which grows on rye Cocaine Atropine treatment for jet lag. The form which is “snorted” relaxes muscles and reduces secretion OH is the hydrochloride salt; the of saliva during surgery; used to Scopolamine N free- “crack” form is dilate pupils for eye examinations. used in treatment of motion N N H A poison from strychnos burned and inhaled, and sickness O reaches the brain in 15 plant (Nux vomica); used H CCH N seconds. 3 3 as a rat and mouse poison HO P N H H O N+ R N OH H N Zephiran chloride OH OH H H (benzalkonium chloride) O O Coniine Antiseptic compound that kills H Inosine Monophosphate (IMP) Poison from hemlock bacteria and fungi on contact With monosodium glutamate (MSG), one of the 25 major substances responsible for the flavor of meat 26

Nitrogen Wastes The disposal of waste nitrogen from the body is a problem which different species of animals have solved in different ways: O H O H OH O NH O N 2 H N NH N 2 HO CH3O CH3 O O O O N N NH2 N N O N O O N H H H H H O O O H Allantoic acid Allantoin N N N Uric acid Marine vertebrates further O Most mammals contain enzymes Birds, reptiles and insects excrete nigrogen metabolyze allantoin into CH3 CH3 CH3 which metabolyze uric acid into wastes in the form of uric acid. Uric acid can allantoic acid. allantoin. be eliminated directly in the solid form, without HO HO CH3 O being dissolved in water. It is produced in the O body from foods and beverages rich in , Found in the opium poppy; a Used in some cough syrups to More fat-soluble than morphine, such as claret and port. Lactic acid inhibits the H H + – CNS depressant; very effective depress the action of the cough and must be injected directly into removal of salts of uric acid in the urine; these NN NH4 X painkiller center of the brain the bloodstream, but crosses the salts instead deposit in the joints, causing gout. Marine invertebrates excrete blood-brain barrier more readily, Dalmations have been bred to have black spots H H salts. causing it to be more potent than with no white hairs in them on their coats; morphine however, the gene which determines the Urea is the major organic presence of white hairs is linked to the gene component of urine; about 25 g which codes the enzyme which breaks down are excreted every day by uric acid into allantoin. Dalmations thus humans. Cartilaginous fish and amphibians also excrete urea. 27 excrete uric acid instead of allantoin, and are 28 very susceptible to gout.

Antihistamines

O NH2 Cl

NN HO H N OH People who are allergic to pollen produce histamine, which causes blood vessels to dilate and leak, releasing fluid into surrounding tissues, causing watery eyes, sniffles, congestion, and other symptoms of hay fever (allergic rhinitis); also N N causes the symptoms of the common cold and swelling after insect bites. OH

Fexofenadine (Allegra®) CH O O 3 A non-drowsy ; available by Loratadine (Claritin®) perscription only N A non-drowsy antihistamine O CH3 CH3

CH3 N

OH H N Diphenylhydramine / N OH an antihistamine; active ingredient in Benadryl; found in the Chinese ma-huang plant; a Cl O sometimes used in sleeping pills decongestant used in many cold remedies Cetrizide (Zyrtec®) A stronger antihistamine than Allegra or O 29 Claritin, but causes drowsiness in some people 30 Chapter 6 Amines and Amides

Bases •A base takes a proton (H+) from another species. A base produces ions, OH–, when dissolved in water: + – B + H2O  BH + OH •A strong base is one that completely dissociates in water (i.e., every molecule of the acid splits apart). •A weak base is one in which only a small Reactions of Amines percentage of the molecules are dissociated at any one time.

+ - • Acidic solution: pH < 7.00 ([H3O ] > [OH ]) + - • Basic solution: pH > 7.00 ([H3O ] < [OH ]) + - 31 • Neutral solution: pH = 7.00 ([H3O ] = [OH ]) 32

Chemical Properties of Amines: Basicity Alkylammonium Salts • Amines are weak organic bases. They react with • Salts of amines are named by changing “amine” to water to produce alkylammonium ions and “ammonium” and adding the name of the negative hydroxide anions: ion to the end of the word: H H H C2H3O2 CH NCHCH R N ++H O R N H OH CH3 NH3 Cl 3 2 3 methylammonium H H H H chloride ethylmethylammonium acetate • and with acids to produce alkylammonium salts: CH2CH3 H H CH3CH2 NCH2CH3 R N + HNCl R HCl H Br H H triethylammonium 33 bromide 34

Alkylammonium Salts Chemical Properties of Amines: Basicity • Salts of amines are generally white crystalline solids • Ammonium salts may be converted back into neutral with high melting points. amines by a strong base: • The ionic charges makes these salts more soluble in + - water than the neutral amines. Many amine- R—NH3 Cl + NaOH  R—NH2 + H2O + NaCl containing drugs are administered in the form of alkylammonium salts to increase their solubility in bodily fluids. H3C H3C H • Thus, by adjusting the pH of the solution, it is - possible to influence whether an amine is present in N HSO4 N the neutral form or as its ammonium cation form:

acid H SO (low pH) + 2 4 + - RNH2 + H2O RNH3 + OH base amine alkylammonium (high pH) ion O O HO OH HO OH Morphine Morphine sulfate 35 36 water-insoluble water-soluble Chapter 6 Amines and Amides

Quaternary Ammonium Salts Examples: Basicity of Amines • In addition to salts of 1°, 2°, and 3° amines, it is • Complete the following reactions: possible to have amine cations which contain four alkyl groups attached to a nitrogen atom, which will CH3NH2 + HCl always carry a positive charge, regardless of the pH of the surrounding solution. These are known as quaternary ammonium salts. NHCH3

R''' CH2CH3 + HCl

+ - + - RR''N X CH3 N CH2CH3 Cl

R' CH2CH3 CH quaternary triethylmethylammonium chloride 3 Cl ammonium salt CH3 N H + NaOH • These salts are present in many antiseptics and antibacterial agents. CH3 37 38

Amides • Amides contain a nitrogen which is directly attached to a carbon in a :

O amide linkage ( bond)

RCN R'

R" Amides Amide

O O O

RCN H RCN CH3 RCN CH3

H H CH3 N,N-unsubstituted amide N-substituted amide N,N-disubstituted amide 39 40

Nomenclature of Amides Examples: Nomenclature of Amides • Amides are named by changing the -oic acid ending • Name the following compounds: of the corresponding to -amide. If O O alkyl groups are attached to the nitrogen, they are named as N-alkyl substituents. CH3 CN CH3 CH3 N C CH3 O O H CH3 O HCOH HCNH2 methanoic acid methanamide C () (formamide) NH2 O CH3 O O CH N C CCH benzamide 3 3 CH3 COHCH3 CNH2 ethanoic acid ethanamide CH3 CH3 (acetic acid) (acetamide)

41 42 Chapter 6 Amines and Amides

Examples: Nomenclature of Amides Examples: Nomenclature of Amides • Name the following compounds: • Name the following compounds:

CH2CH3 OCH3 OCH3 CH3CH2CH2CHCH2 CN CH2CH3 CH3CH2CH2 CN CH2CH3

NH2 O CH3

CH3CH2CH2CHCH C N CH3 CH3 OCHCH2CH3 2CHCH3 CH H 3 CH3 N C CHCH2CH2CCH3

CH3 43 44

Examples: Nomenclature of Amides Examples: Nomenclature of Amides • Name the following compounds: • Name the following compounds:

O O

C CH3 C CH N N CH3 3 H H

O O

C CH3 C N CH N CH3 3 CH CH3 3

CH3 45 46

Examples: Nomenclature of Amides Examples: Nomenclature of Amides • Draw structural formulas for the following molecules: • Draw structural formulas for the following molecules: – 2-methylpropanamide – N,2-diethylbenzamide

– N,2,4-trimethylpentanamide – N,N,2,3,4-pentamethylbenzamide

– N-ethyl-N-methylacetamide – N,N,4,4-tetramethylbutanamide (what’s wrong with this name?)

47 48 Chapter 6 Amines and Amides

Physical Properties of Amides • N,N-unsubstituted amides can form a complex network of hydrogen bonds. They tend to have high melting points and also high boiling points. O

RCN H

H Physical Properties of H Amides O NH RCN H O C

H R

O

RCNH 49 50 H

Physical Properties of Amides Examples: Predicting Physical Properties • N-substituted amides often have lower melting • Arrange the following compounds in order of points and boiling points than N,N-unsubstituted increasing boiling point. (All of the compounds amides because fewer hydrogen bonds can form. have about the same molecular weight.) • N,N-disubstituted amides cannot form hydrogen N-ethylethanamide bonds, and have even lower melting points and boiling points. butanamide • All amides can hydrogen bond with water, so low- N,N-dimethylethanamide molecular weight amides are water-soluble.

Boiling Point: N,N-unsubstituted amides N-substituted amides N,N-disubstituted amides

51 52

Important Amides

H O O N N

CH2CH3 Cl N O ON OON CH2CH3 H Important Amides Thalidomide Until 1956, a very popular, safe sedative; the largest market was for Diazepam (Valium) CH 3 pregnant women who were A benzodiazepene experiencing morning sickness. tranquilizer; acts by N,N-Diethyl-m-toluamide However, it caused massive birth enhancing the inhibitory Active ingredient in OFF defects in women who used it in the GABA; early states of pregnancy, and was since it binds to the same banned in Europe; it was never as , authorized for sale in the U.S. combinations of valium and ethanol can be deadly

53 54 Chapter 6 Amines and Amides

Hot Stuff Barbiturates

O H O H O NCS N N O CH O 3 Allyl S N N Capsaicin Used in horseradish flavor, N H Found in red and green chili mustard oil, pickles, salad O H HO peppers; active component of dressings and sauces; mustard Barbituric acid O H paprika plasters, medications and First synthesized by Adolf von Baeyer in 1864; Thiopental (Pentothal) fumigants barbiturates are soporifics, and are used as An intravenous anesthetic tranquilizers and anesthetics; many are also addictive, and overdoses can be fatal. (Other barbiturates include Seconal, Veronal, Phenobarbitol, Thiopental, Amobarbitol, etc.) O O O O H O H Component of white and CH3O black pepper N N N O O HO Zingerone N The pungent, hot component of ginger N O O H O H Amobarbital (Amytal) Phenobarbitol Used in the treatment of insomnia Anti-seizure medication, sedative 55 56

Sulfa Drugs Penicillin

N O O R =

N SNH2 H2N SNH2 NH H Penicillin G 2 O O O Prontosil Sulfanilamide N OOH S O CH3 R OH O O Penicillin V N N CH3 O H H O OH O N CO2H H N Folic acid H N N 2 Penicillin Ampicillin para-Aminobenzoic aid (PABA) NH2 H2N N N OCH Penicillin is an antibiotic compound produced by 3 Sulfanilamide, the first antibiotic, was discovered by Gerhard Damagk (Nobel Prize, the molds Penicillium notatum and Penicillium 1939), who observed the antibacterial action of the red dye Protonsil; further researched chrysogenum; it was discovered by Alexander showed that it was the metabolic byproduct, sulfanilamide, which was the active form. Fleming in 1928 in a culture of bread mold. There Methicillin It prevents bacteria from synthesizing folic acid, which they need in order to grow. are several varieties: Penicillin G and Methicillin Bacterial enzymes synthesize folic acid using para-aminobenzoic acid (PABA); are administered by injection; Penicillin V is an sulfanilamide fits into the enzyme more tightly, blocking it from taking up PABA, and oral form which is not broken down in the OCH3 thus blocking folic acid synthesis. The bacterium cannot grow, and eventually dies. stomach; Ampicillin is a broad spectrum penicillin Humans obtain folic acid from their diet (an essential ), so sulfa drugs do not which can be administered by injection or orally harm people in this way (although they can cause allergic reactions). 57 58

Molecules To Dye For Molecules To Dye For • Dyes are compounds that can be used to color other materials, such as clothing, paper, hair, etc. CH NCH • Many organic dyes contain a long series of double bonds that are close 3 3 together. If the chain of double bonds is long enough, these molecules can absorb low-energy light in the visible region of the electromagnetic H spectrum, resulting in colors that are visible to the human eye. N N NH2 2_ SO4 O H O H

N N Br

CH3 2 N Br N Mauve HO HO This is the first of the synthetic dyes. It was discovered by the Indigo Tyrian purple 18-year-old English chemist William Henry Perkin in his home A naturally occurring blue dye which has been 6,6'-dibromoindigo laboratory, while attempting to synthesize quinine (the only known used for thousands of years. It is obtained Tyrian purple, or “royal purple,” is a purple dye treatment for malaria at that time). While cleaning up the sludge from an Indian plant (Indigofera tinctoria) and originally obtained from a species of mollusk (Murex) from one of his failed attempts, he noticed that the sludge was turning the European woad (Isatis tinctoria). Today, found near the cities of Tyre and Sidon in ancient the water in his sink violet, and that cloth would pick up this purple indigo can be made synthetically, and is used Phoenicia. It took about 9,000 mollusk shells to color. Perkin patented his serendipitous discovery, and went into in dyeing denim to make blue jeans. obtain one gram of the dye, making it very expensive. business making dyes, becoming so successful that he was able to This dye was used by royalty (hence the name “royal retire at the age of 36 to focus his attention on chemical research. purple”) and the Roman aristocracy. 59 60 Chapter 6 Amines and Amides

FD&C Dyes FD&C Dyes

NaO3S These color additives are approved by the Food and Drug Administration NaO S (FDA) under the Federal Food, Drug, and Cosmetic Act (FD&C, 1938, 3 amended 1997) for use in foods. CH3 OCH3 O H

NaO3S N NN NN - SO Na SO3 3 SO3Na N SO Na HO 3 HO HO CO Na FD&C Blue No. 2 FD&C Red No. 40 2 NaO3S SO3Na FD&C Yellow No. 6 N N Indigo Carmine, Indigotine Allura Red AC N Sunset Yellow FCF FD&C Blue No. 1 N Brilliant Blue FCF N NaO3SN II OH HO NaO O O FD&C Yellow No. 5 SO Na Tartrazine 3

CO2CH2CH3 CH OCH I I 3 3 - SO3 N CO2Na N NN N NaO3S N NaO3S SO3Na HO HO N N FD&C Red No. 3 Erythrosine Orange B SO3Na FD&C Green No. 3 Used in sausage and Citrus Red No. 2 Fast Green FCF 61 frankfurter casings Used to color orange skins 62

Molecules To Dye For Molecules To Dye For O CH3 H3C CH3 N N N N

CH3 NSO3Na N Methyl orange HO O O NNO2 Resazurin OH OH Para red N CH3 O CH N N 3 Cl N N CH3 CH3 Cl CH N H3C CH3 3 N S N N N Methyl red CH3 N CH Methylene Blue CH 10B Butter yellow 3 3 CH3 (crystal violet) CH3

OH HO NH2 H2N

N N N N N N N N HO3S NH2 H2N SO3H O O S S CH3O Chicago blue OCH3 O O NaO Congo red ONa SO3H HO3S 63 64

Amide Formation • Amides are formed when acid chlorides react with 1° or 2° amines; 3° amines cannot form amides: OOHH

RCCl + R' N H RCNR'+ HCl

Reactions of Amides OOR'' R''

RCCl + R' N H RCNR'+ HCl

O R''

RCCl+ R'N R''' no reaction 65 66 Chapter 6 Amines and Amides

Amide Formation Examples: Formation of Amides • Amides are also formed when acid anhydrides react • Complete the following reactions: with 1° or 2° amines. O CH3 O O HHO O CCl+ CH3 NH RCOCR+ R' N H RCNR'+ HO C R

O O R''O R'' O

RCOCR+ R' N H RCNR'+ HO C R

O O R''

RCOCR+ R'N R''' no reaction

67 68

Examples: Formation of Amides Examples: Formation of Amides • Complete the following reactions: • Complete the following reactions:

O O O CH3

CH3 CO C CH3 + CH3CH2CH2NH2 CH3 CCl+ CH3 NCH3

69 70

Chemical Properties of Amides Examples: Reactions of Amines and Amides • Unlike amines, amides are not basic. • Complete the following reactions:

• Amide hydrolysis can take place under acidic or O H basic conditions: CH3 C NCH3 ++HClH2O O R'' O R''

+ - RCNR'++H2O HCl RCOH + H N R' Cl

H O H

O R''O R'' CH3 C NCH3 + NaOH

RCNR'++NaOH RCO- Na+ H NR'

71 72 Chapter 6 Amines and Amides

Condensation Polymers: Polyamides O O H N(CH) NH H N(CH) NH 2 2 6 2 C (CH2)10 C 2 2 6 2 1,6-diaminohexane Cl sebacoyl chloride Cl 1,6-diaminohexane

O O

C (CH2)10 C

H2N(CH2)6 N N(CH2)6 NH2 H H

O O O O O O Condensation Polymers: C (CH2)10 C C (CH2)10 C C (CH2)10 C Cl N (CH2)6 N N(CH2)6 N Cl H H H H

Polyamides O O O O O O

C (CH2)10 C C (CH2)10 C C (CH2)10 C

H2N(CH2)6 N N (CH2)6 N N(CH2)6 N N(CH2)6 NH2 H H H H H H

O O O O O O O O O O

C (CH2)10 C C (CH2)10 C C (CH2)10 C C (CH2)10 C C (CH2)10 C

Cl N (CH2)6 N N (CH2)6 N N(CH2)6 N N(CH2)6 N Cl H H HHH H H H

73 74 etc.

Condensation Polymers: Polyamides Polyamides O O

C (CH2)10 C

NH2 O Cl NH—(CH2)6—HN H n -6,12 H H N a 2 N Discovered by Wallace Carrothers at DuPont in 1934; polymers + O average about 10,000 g/mol; 3 billion pound of Nylon made per O O year; 60% used for nylon fiber in home furnishings (carpet); also N used in textile fibers, tire cord, rope, parachutes, paint brushes, Cl H Velcro, electrical parts, medical applications (sutures, etc.) Kevlar Cl used in bullet-proof vests and tire cords O O O O O (an aramid, "aromatic polyamide") C NNCC NNC O HHH H O O O O

C NNCC NNC

HHH H O O O O

C NNCC NNC 75 76 HHH H

Polyamides

RNCO RNCO O HOR H OR C H2N NH2 Isocyanate + A Urethane N

O O O O OH H3CNCO + HO OH O O N N Toluene diisocyanate Glycerol H H Cl Cl OH

Nomex O OH Insulates ceramic tiles on the space shuttle; used in firefighting equipment, race car driver suits, flight suits, the airbags on the Mars O C Pathfinder, Spirit, and Opportunity rovers (less strong than Kevlar, but has excellent thermal, chemical, and radiation resistance) HN OH

O OH H C H C 3 N O 77 78 A Chapter 6 Amines and Amides

Neurotransmitters • are small molecules that carry nerve impulses from one neuron to the next. • Neurons consist of the main cell body (the soma), long stemlike projections (the axons), and short fibers connected to the soma (the dendrites). • Neurons are not connected directly to each other, but are separated by a small gap called a synapse. Neurotransmitters • When an electrical current originating in a neuron reaches the synaptic terminals at the end of the axon, the terminals release neurotransmitter molecules into the synapse; these molecules diffuse across the synapse and bind to receptors on the dendrites of the next neuron, stimulating an electrical current, which travels along that neuron until it reaches the next synapse, and so on until the 79 nerve impulse reaches the brain. 80

Figure 6.5 A nerve cell HO and the transmission of a nerve signal. HO HO NH2

CO2H Dopa HO NH Synthesized from the amino acid tyrosine; used as a 2 treatment for Parkinson's disease, which is caused by a breakdown of dopamine-based neurons that control the Synthesized from dopa; used as a brain's motor system (dopamine cannot be administered treatment for low blood pressure directly because it does not cross the blood-brain barrier; however, the L-form of dopa does)

HO

NH2

HO NH2 N OH H (NE) Synthesized from dopamine; an excess of NE in the Synthesized from the amino acid ; brain is related to feelings of elation or manic states; influences sleeping, body temperature, and low NE levels are linked to depression; the stimulant sensory perception; drugs that mimic serotonin action of epinephrine and NE in some cells can be are used to treat depression, anxiety, and reduced by beta blockers, which are used to treat obsessive-compulsive disorder; serotonin cardiac arrhythmias, angina, and hypertension blockers are used to treat migraine headaches 81 and nausea resulting from 82

Pheynlephrines and

HO

CH3 CH3 CH3 CH 3 CH HO N 3 CH3 NH2 N N OH H (Benzedrine) H OH H Epinephrine (Adrenalin) a powerful nervous stimulant; raises N-Methylamphetamine More important as a hormone than a neurotransmitter; blood glucose levels, increases heart (Methedrine, "speed") Ephedrine / Pseudoephedrine synthesized in the adrenal glad; release of adrenalin into rate and blood pressure Also a powerful nervous found in the Chinese ma-huang plant; a the bloodstream in response to pain, anger, or fear stimulant decongestant used in many cold remedies increases blood glucose levels, and provides a sudden burst of energy (fight-or-flight response); increases force of heart contractions (raising blood pressure); also a vasoconstrictor; used in local anesthetics to keep the O CH anesthetic from being washed away 3

CH3 CH3 HO N O N O CH O O CH 3 3 CH3 OH H H H N + 2 CH3O 3,4-Methylenedioxymethamphetamine N OH (MDMA), "Ectasy" O CH3 Common decongestant Acetylcholine Gamma-aminobutanoic acid (GABA) A inhibitory neurotransmitter CH3O NH2 Mescaline 83 Hallucinogen from peyote cactus 84 Chapter 6 Amines and Amides

Amino Acids O H H2N OH

R Amino Acids

O O O O

H2N H2N H2N H2N OH OH OH OH Amino Acids and (Gly) CH3 (Ala) (Val) Proteins (Leu)

O O H O O

H2N H2N N H2N OH OH OH OH

S (Pro) (Ile) Methionine (Met)

85 Phenylalanine (Phe) 86

O O O O O

H N H N H N H N H2N 2 2 2 O 2 OH OH OH OH OH

H2N OH OH O OH OH O O (Ser) (Thr) H CH3 H2N O H2N Alanine (Ala) N OH N OH Aspartate (Asp) Tyrosine (Tyr) H Glycine (Gly) OH Tryptophan (Try) Glycine (Gly) O O O O CH3 Alanine (Ala)

H2N H2N H2N H2N OH OH OH OH O O H N NH2 2 SH OH NH NH Cysteine (Cys) 2 Glutamine (Gln) N O O H O (His) (Asn) H2N H O O O O O N Glycine (Gly) N N OH H H2N H2N H2N H2N Tryptophan (Try) OH OH OH OH O CH3 O Alanine (Ala) OH NH2 OH N NH2 Lysine (Lys) OH H O Glutamate (Glu) Arginine (Arg) O 87 Aspartate (Asp) 88 Aspartate (Asp)

O H O H2N H O N H O Glycine (Gly) N N CH3 OH Alanine (Ala) OH etc.

O Aspartate (Asp) N H Tryptophan (Try)

Gly Ala Asp Try a protein (a polyamide) Instructions for making proteins are encoded in DNA.

89 Three levels of structure in a telephone cord 90 Chapter 6 Amines and Amides

Segment of a protein showing -helix, -pleated sheet, R-group interactions leading to a protein tertiary structure 91 and random coil structures 92

O

OH O

O N(CH3)2 H OH O H Some Hideously Complex Erythromycin an antibiotic O

OCH3 Molecules OH H H N NH CH3 OH 2 H2N N H N OH NH H NH O H O HO OH H H OH O O CHO Streptomycin OH OH 93 an antibiotic CH3 94

O O H2N O

OO O OH CH3 NH2 O CH3 O H2N H C NH HN O 3 N N 2 O H H3C N OH H Co O HO O H H O O O NN Taxol CH3 NNH2 potential anti-cancer CH drug isolated from the 3 Pacific yew tree O O H2N Bufotoxin O O CH3 CH3 isolated from the toad Bufo O NH OH marinus; increases the 2 Vitamin B12 (cobalamine) contractive power of weak O Found in meat, fish, eggs, and milk; a O N heart muscles; also causes NH H terrifying hallucinations coenzyme involved in amino acid metabolism; needed for the production O of red blood cells (a deficiency in N vitamin B12 results in anemia) O H3CPO O OH N O O CH3 OH O O HO O 95 96 CH3 Chapter 6 Amines and Amides

O O O Functional Groups O O O OH - + H H R COHRCO M R COR RCCl RCOCR R R carboxylic acid salt acid chloride acid anhydride H CCH CC R CCR (-oic acid) (metal + -oate) (alkyl + -oate) H H RR alkane aromatic ring (-ane) (-ene) (-yne) (phenyl-, -) (-phenol) R

RHN RHN RRN RRN+ H H R H R R R ROHC ROHC ROHC ROR R SH primary (1°) amine secondary (2°) amine tertiary (3°) amine quaternary ammonium salt (amino-, -amine) (-amine) (-amine) (alkyl ammonium + anion) H R R (alkoxy-, -ether) primary (1°) alcohol secondary (2°) alcohol tertiary (3°) alcohol (-ol) (-ol) (-ol)

O O O O O O OH OR OH OR RCNH2 RCNHR R C N R RO POH RHC RHC RRC RRC RCH R CR R OH OR OR OR OR amide phosphate ester (-al) (-one) hemiacetal hemiketal ketal 97 (N-alkyl + -amide) 98

Reactions of Amines and Amides 4. Formation of an amide. (NR with tertiary amines.) OORR 1. Reaction of an amine with water to produce an alkylammonium ion. H H R' C Cl+ RH N R'CNR+ HCl acid chloride amine amide -OH R N + H O R N H + (1° or 2°) H H H O OORRO amine alkylammonium ion R' C OCR+ RH N R'CNR+ R' C OH acid anhydride amine amide carboxylic (1° or 2°) acid 2. Reaction of an amine with acid to produce an alkylammonium salt. H H 5. Hydrolysis of amides under acidic and basic conditions. OOH R N + HNCl R H -Cl + - R' C N R++H2O HCl R' C OH + H N R Cl H H carboxylic amine hydrochloric alkylammonium R acid R acid chloride amide alkylammonium salt OO

3. Conversion of an alkylammonium salt back to an amine. R' C N R+ NaOH R' C O- Na+ + H N R + - R—NH3 Cl + NaOH  R—NH2 + H2O + NaCl carboxylate R salt R amide 99 amine 100

The End

101